Step 1: Preheat Oven and Prepare Pan.

Preheat the oven to 350°F (175°C).

Line a cupcake tin with liners.

Step 2: Prepare Dry Ingredients.

In a small bowl, whisk together the sifted flour, baking powder, and salt.

Zest the lemons and set the zest aside.

Step 3: Cream Butter and Sugar.

In the bowl of your electric mixer, beat the softened butter until creamy.

Add in the sugar. Beat on medium speed, scraping down the sides if needed.

Increase the speed to high and beat for 2 to 3 minutes, until the mixture is light and fluffy.

Step 4: Add Eggs and Extracts.

Beat in the egg and egg whites, one at a time, until incorporated.

Add the vanilla extract and lemon extract (if using).

Add the lemon zest. Beat until combined.

Step 5: Alternate Adding Dry and Wet Ingredients.

With the mixer on low speed, add in half of the dry ingredients. Beat until combined.

Add in the milk and lemon juice. Beat until combined.

Add in the remaining dry ingredients. Beat until just combined. Don’t overmix.

Step 6: Bake the Cupcakes.

Using an ice cream scoop or a 1/4 cup measure, scoop the batter into the prepared cupcake liners.

Fill them about 3/4 of the way full.

Bake for 16–18 minutes, or until the tops are set and a toothpick inserted into the center comes out clean.

Step 7: Cool the Cupcakes.

Let the cupcakes cool in the tin for a few minutes.

Then, transfer them to a wire rack to cool completely.

Step 8: Make the Lavender Frosting.

Add the softened butter to the bowl of your electric mixer fitted with the paddle attachment. Beat until creamy.

With the mixer on low speed, gradually add the powdered sugar and finely chopped lavender.

Increase the speed of the mixer, scraping down the sides if needed. Beat until the frosting is fluffy and combined.

Beat in the vanilla extract.

If the frosting seems too thick, beat in the tablespoon of milk or cream.

If it seems too thin, add more powdered sugar, 1/4 cup at a time.

Once the frosting is a spreadable consistency, drop in the purple food coloring (if using). Mix until evenly colored.

Step 9: Frost and Garnish.

Frost the completely cooled cupcakes with the lavender frosting.

Top with a few fresh lavender flowers, if desired.